The present disclosure relates to a gas turbine engine, and more particularly to a turbofan engine having a variable area fan nozzle (VAFN).
Gas turbine engines which have an engine cycle modulated with a variable area fan nozzle (VAFN) provide a smaller fan exit nozzle during cruise conditions and a larger fan exit nozzle during take-off and landing conditions.
Often during re-engining studies one main goal is to package the largest possible fan onto a preexisting aircraft in order to maximize the fuel burn benefit. Additionally, as fan diameter grows and fan pressure ratio drops to achieve better fuel efficiency for a given thrust level, a VAFN is utilized to manage fan operability. The VAFN requires actuators which may limit the size of fan that can be installed onto a pre-existing aircraft.